De-Carb Question
Thread Starter
Melting Slicks
Joined: Dec 2004
Posts: 2,322
Likes: 2
From: New York NY
Cruise-In VI Veteran
St. Jude Donor '05
De-Carb Question
I was considering doing a de-carbonization using the top engine cleaner from GM. I was planning on following the procedure I have heard many times on the forum: open the pcv valve, pour two cans of top engine cleaner in while the car is running at idle, let it sit over night, then do an oil change. I dont have any knocking or pinging (car has 38K miles).
I spoke with a GM tech who mentioned that this is not a safe way to do the decarb and it probably isnt even necessary. He said the proper way would be to remove the spark plugs, pour in the engine cleaner that way, and manually turn the engine over.
Are these procedures correct? Should the decarb really be done with the engine running? How do you know if you actually need to do a decarb? thanks in advance
I spoke with a GM tech who mentioned that this is not a safe way to do the decarb and it probably isnt even necessary. He said the proper way would be to remove the spark plugs, pour in the engine cleaner that way, and manually turn the engine over.
Are these procedures correct? Should the decarb really be done with the engine running? How do you know if you actually need to do a decarb? thanks in advance
Last edited by Icemanskis; Oct 10, 2005 at 11:11 PM.
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Yes the engine has to be running. If you have alot of miles it may need to be done. But the engine has to be running in order to burn the carbon out, if not you can water lock the engine.
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Originally Posted by Icemanskis
I was considering doing a de-carbonization using the top engine cleaner from GM. I was planning on following the procedure I have heard many times on the forum: open the pcv valve, pour two cans of top engine cleaner in while the car is running at idle, let it sit over night, then do an oil change. I dont have any knocking or pinging (car has 38K miles).
I spoke with a GM tech who mentioned that this is not a safe way to do the decarb and it probably isnt even necessary. He said the proper way would be to remove the spark plugs, pour in the engine cleaner that way, and manually turn the engine over.
Are these procedures correct? Should the decarb really be done with the engine running? How do you know if you actually need to do a decarb? thanks in advance
I spoke with a GM tech who mentioned that this is not a safe way to do the decarb and it probably isnt even necessary. He said the proper way would be to remove the spark plugs, pour in the engine cleaner that way, and manually turn the engine over.
Are these procedures correct? Should the decarb really be done with the engine running? How do you know if you actually need to do a decarb? thanks in advance
Good luck..
Rsty
Race Director
Joined: Sep 2002
Posts: 14,515
Likes: 24
From: Washington County, South UTAH
We did it on a couple of cars, years ago. Tech ran some in while running, then removed all spark plugs. He poured a little in each cylinder and let it sit overnight. In the morning, he installed new spark plugs and fired it up. You could hear the carbon rattling out for a few moments. Fixed detonation problem.
God Bless America!
God Bless America!
Race Director
Joined: Apr 2001
Posts: 19,329
Likes: 15
From: Saint Augustine, FL
Mid-TN Events Coordinator
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
I don't know...some of these 'pour some in the spark plug holes' recommendations sounds like trouble. Pour a little too much in one of the cylinders, BAM, there go the rings. I'm not sure how 'metered' the PCV method is, but that sounds like it would be the safer way, assuming it's not sucking in the entire bottle in a short time.
I'm with the PCV guys. I haven't done it yet on my car, but I will at some point.
I'm with the PCV guys. I haven't done it yet on my car, but I will at some point.
Heel & Toe
Joined: Oct 2005
Posts: 17
Likes: 0
in the spark plug is recomended because you cannot hydrolock the engine if the plugs are out. remember instruction are often written to make sure nothing stupid happens. obviously if you dump a ton in there is the chance of hydolocking the engine when it is running. use some common sense. plain water also works wonder on the intake valves. the top cleaner does a nice job on rings/pison crowns
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
